We will continue our studies of fatty acid synthesis and desaturation in lung tissue in vitro from rats fed regular chow, or fat free diets supplemented with 4% safflower oil or 4% tripalmitin, as well as from fetuses of female rats made diabetic with streptozotocin. Slices will be incubated with 1-14C acetate or palmitate and incorporation of label with tissue lipids, including fatty acids, triglycerides, phospholipids and disaturated phosphatidyl choline and phosphatidyl glycerol will be determined. The extent of desaturation of fatty acids will be determined using argentation chromatography and GLC. Similar studies will be performed using Type II cells isolated from lungs of these animals. In addition we will continue our studies on the fatty acid composition of lecithins isolated from bronchial lavage fluid of patients with ARDS secondary to body trauma, head injury or sepsis. Content of PG in lavage fluid will also be evaluated. The data will be correlated with physiologic measurements of lung function (FRC and % shunt) in these patients.